Tarzan and the Golden Lion is the ninth book in Edgar Rice Burroughs' series of novels about the jungle hero Tarzan.
In the previous novel, Tarzan rescued Jane after he discovered that she was alive, and was reunited with his son Korak. In this story, Tarzan has been drugged and delivered to the priest of Opar, the lost colony of Atlantis that Clayton had last visited in Tarzan and the Jewels of Opar. Once again the High Priestess of the Flaming God, La, who is consumed by her hopeless lust for Tarzan, rescues him. But when her people discover that she had betrayed them, Tarzan flees with La into the legendary Valley of Diamonds, where savage gorillas rule. The good news is that Tarzan and La were being followed by Jad-bal-ja, his faithful golden lion whom he had raised from a cub. The bad news is that they are also being followed by Estaban Miranda, who happens to look exactly like Clayton, but who is evil.